The Dallas Cowboys enter 2019 with a roster stack full of superstars, stars, and high-quality starters. The team is coming off of their second playoff birth, led by Dak Prescott and Ezekiel Elliot for the second time in three years and looks the part of a contender. But, that doesn't mean they don't have their fair share of starters and former high-round picks needing to take the next step.

Here are three of the players that the Cowboys need to step up during the 2019 season.

3. Taco Charlton – DE

The Cowboys brought in Robert Quinn to supplement the pass rush adjacent Demarcus Lawrence, but he’s not a long-term option. Randy Gregory, now out due to an indefinite suspension, isn’t either. Taco Charlton, their first-round pick in 2017, could be; but he hasn’t shown it since being drafted. In two years of play, the former Michigan product has tallied just four career sacks.

Taco started his rookie year slowly, but he came into his own during the second half of the season; in the last five weeks, he recorded a pair of sacks, eight total tackles, and six QB hits. The expectation as a sophomore was that he’d take the next step in a rotational role. Charlton ended his second year with one sack and played limited snaps when the Cowboys stepped up their playoff push, and arrival.

Charlton—standing at 6-foot-6 and 270-pounds—has the tools to thrive in Dallas. He’s lengthy, athletic, and appears to have a quality first step. But injuries, a work ethic that’s been questionable, and inability to get the passer have buried him in the depth chart and has given Charlton a bust label. He’ll probably be on the roster through 2019, but if he wants that expensive fifth-year option for 2022, Charlton will need to show more than he has early in his career.

2. Connor Williams – LG

Many figured former Texas left tackle Connor Williams would be a first-round pick, but not at the same position. Half of that ended up being true. The offensive lineman fell to the Cowboys in the second-round in the 2018 draft, where he wouldn’t have to play left tackle. The ‘Boys moved him to guard, sticking him at the left side, where he’ll start come 2019.

Williams showed flashes of why he got drafted highly, but most of his rookie year—like most first-year offensive lineman—was hard to watch. He started ten games, played 13, and allowed 32 pressures on Dak Prescott, per Pro Football Focus. Williams ended the year as the same analytics firm’s 51st best guard in the NFL, earning an average grade.

Williams appears to be the Cowboys’ long-term plan at left guard, and for a good reason. His 6-foot-5, 298-pound frame is an asset, and so is his physicality and mauling-mentality. But he’s going to have to show more comfort, and proficiency playing the position. Though Dallas has an already solid line in place with their fearsome threesome of Tyrone Smith, Zach Martin, and a healthy Travis Frederick, the hope is that Williams along with La’el Collins gives completeness to the unit.

1. Jeff Heath – S

For the past two years, one of the first to blame for the Cowboys’ subpar over the top pass-defense has been safety Jeff Heath—and for a good reason. Starting the past two years, the safety has been a liability for the defense down in Dallas. He’s noted as possessing an inability to tackle in the open field, one of the essential things a strong safety—his position—can do.

According to Football Outsiders, Heath missed 11 tackles in his first year starting (2017), five more than his defeats. Then, in 2018, he doubled that number to 22 (PFF saw it as 19); the second highest in the NFL. PFF gave the same season a 56.4 grade, good for 81st in the NFL amongst all safeties. Though he was once a solid special-teamer (and still is), his play as a starter has lost himself some fans.

Heath is on the hot-seat entering 2019—the team signed career starter George Iloka and drafted Texas A&M’s Donovan Wilson—but he’s still billed as the starter. However, unless he progresses mightily, the Cowboys will surely look for his replacement throughout training camp and pre-season. He’s simply a liability and the team’s biggest weakness on defense.